Heat control for gas-fractionating column



Fel 26, A1963 J. VAN DER STER Erm. 3,078,684

Y HEAT CONTROL FOR GAS-FRACTIONATING COLUMN Filed April 22, 1959 Fig.2

ill,

Fig. 3

i2. WATER f souRcE INVENTORS .JOHANNES VAN DER STER JACOB w. L. KOHLER AG NT fractionating air, is 86 K. for oxygen). In this case less heat is supplied to pump 16.

At the level cc, the temperature at 2S is further reduced to say, 90 K. The supply of the pump 16 further decreases and the level no longer rises in the boiler.

The varying thermal resistance of the control member 26 should be properly chosen.

It has been found that a substantially conical pin yields excellent results.

Alternatively, other forms are possible. Thus, for example, FIG. 3 shows a block 35 of conductive material having secured to it a number of strips 33 having different lengths. The thermal resistance of this block forms a level a-a to the area 34, where the block 35 passes through the wall of the boiler, is also variable at diierent levels.

What is claimed is:

1. A gas fractionating apparatus co-acting with a thermal sink comprising an insulated column having a boiler in the bottom thereof, said thermal sink being adapted to carry od vaporfrom said column and condense the same, a distributor for condensate returning to said column, conduit means in the insulated portion of said column connecting said thermal sink to the upper part of said column, said conduit means communicating with said distributor for the condensate returning to said column and a vapor lift pump in the insulated portion of said column operatively connected to said distributor, a heat conductive member in said column having an external source of applied heat and being in heat conducting relationship with said vapor lift pump, said returning condensate being conducted to the lower end of said vapor lift pump whereby said condensate is caused to rise therein due to said source of applied heat until it spills into said column, a portion of said heat conductive member being adapted to assume a temperature higher than that of said condensate, a control element in said boiler for automatically controlling the level of liquid in the boiler being reduced in cross-section at the end closest to the bottom of said boiler, said heat conductive member being operatively connected to said element, said control element being in heat exchanging contact with the liquid in said boiler, and said reduced end of the control element being so shaped and proportioned that the thermal resistance of the element varies at different distances between the junction of the element with the heat conductive member and the liquid level inside said boiler.

2. A gas fractionating apparatus as claimed in claim l wherein the thermal resistance of said control element is such as to prevent oscillation during control.

3. A gas fractionating apparatus co-acting with a thermal sink comprising an insulated column having a boiler in the bottom thereof, said thermal sink being adapted to carry ofi vapor from said column and condense the same,

a distributor for condensate returning to said column, con duit means in the insulated portion of said column connecting said thermal sink to the upper part of said column, said conduit means communicating with said distributor for the condensate returning to said column and a vapor lift pump in the insulated portion of said column operatively connected to said distributor, a heat conductive member in said column having an external source of applied heat and being in heat conducting relationship with said vapor lift pump, said returning condensate being conducted to the lower end of said vapor lift pump whereby said condensate is caused to rise therein due to said source of applied heat until it spills into said column, a portion of said heat conductive member being adapted to assume a temperature higher than that of said condensate, a control element in said boiler shaped as a conical pin for controlling the contact of said member with the liquid in said boiler, an enclosure for said control element having apertures therein, said control element being in heat exchanging contact with the liquid in said boiler, and said conical control element being so shaped and proportioned that the thermal resistance of the element varies at different distances between the junction of the element with the heat conductive member and the liquid level inside the boiler.

4. A gas fractionating apparatus co-acting with a thermal sink comprising an insulated column having a boiler in the bottom thereof, said thermal sink being adapted to carry oit vapor from said column and condense the same, a distributor for condensate returning to the column, conduit means in the insulated portion of said column connecting said thermal sink to the upper part of said column, said conduit means communicating with said distributor for the condensate returning to said column and a vapor lift pump in the insulated portion of said column operatively connected to said distributor, a heat conductive member in said column having an external source of applied heat and being in heat conducting rela tionship with said vapor lift pump, said returning condensate being conducted to the lower end of said vapor lift pump whereby said condensate is caused to rise therein due to said source of applied heat until it spills into said column, a portion of said heat conductive member being adapted to assume a temperature higher than that of said condensate, a control element in said boiler shaped as a conical pin for controlling the contact of said member with the liquid in said boiler, an enclosure for said control element having apertures therein, said control element being in heat exchanging contact with the liquid in said boiler, and said conical control element being so shaped and proportioned that the thermal resistance of the ele ment varies at different distances between the junction of the element with the heat conductive member and the liquid level inside said boiler, said conical pin having a tapering point projecting in the direction of the liquid in the boiler, and a thermally insulated lead-through member having said conical pin passing therethrough and secured to said heat conductive member.

5. A gas fractionating apparatus co-acting with a thermal sink comprising an insulated column having a boiler in the bottom thereof, said thermal sink being adapted to carry off vapor from said column and condense the same, a distributor for condensate returning to the co1- umn, conduit means in the insulated portion of said column connecting said thermal sink to the upper part 0f said column, said conduit means communicating with said distributor for the condensate returning to said column and a vapor lift pump in the insulated portion 0f said column operatively connected to said distributor, a heat conductive member in said column having an external source of applied heat and being in heat conducting relationship with said vapor lift pump, said returning condensate being conducted to the lower end of said vapor lift pump whereby said condensate is caused to rise therein due to said source of applied heat until it spills into said column, a portion of said heat conductive member being adapted to assume a temperature higher than that of said condensate, a control element in said apparatus for controlling the contact of said member with the liquid in said boiler, an enclosure for said control element having at least one opening for the passage of liquid therethrough, said enclosure being located in said boiler, said control element having a reduced cross-section at the end thereof closest to the bottom of the boiler being in heat exchanging contact with the liquid in said boiler, and the reduced end of said control element being so shaped and proportioned that the thermal resistance of the element varies at different distances between the junction of the element with the heat conductive member and the liquid level inside said boiler.

6. A gas fractionating apparatus co-acting with a thermal sink comprising an insulated column having a boiler in the bottom thereof, said thermal sink being adapted to carry olf vapor from said column and condense the same, a distributor for condensate returning to the col umn, conduit means in the insulated portion of said column connecting said thermal sink to the upper part of said column, said conduit means communicating with said distributor for the condensate returning to said column and a vapor lift pump in the insulated portion of ysaid column operatively connected to said distributor, a heat conductive member in said column having an external source of applied heat and being in heat conducting relationship with said vapor lift pump, said returning condensate being conducted to the lower end of said vapor lift pump whereby said condensate is caused to rise therein due to said source of applied heat until it spills into said column, a portion of said heat conductive member being adapted to assume a temperature higher `than that of said condensate, a control element in said apparatus being a block of conductive material having heat conducting strips of various lengths extending in the direction of the liquid in the liquid boiler, an enclosure for said control element having apertures therein,

said control element being in hea-t exchanging contact with the liquid in said boiler, and said heating conducting strips of said control element being so shaped and proportioned that the thermal resistance o-f the element varies at different distances between the junction of the element with the heat conductive member and the liquid level inside said boiler.

References Cited in the tile of this patent UNITED STATES PATENTS 820,429 May May 15, 1906 1,716,838 Shotter June 11, 1929 2,230,137 Ewertz Jan. 28, 1941 2,799,141 `Tonkers et al. July 16, 1957 2,889,686 Kohler June 9, 1959 2,919,556 Mulder Jan. 5, 1960 

1. A GAS FRACTIONATING APPARATUS CO-ACTING WITH A THERMAL SINK COMPRISING AN INSULATED COLUMN HAVING A BOILER IN THE BOTTOM THEREOF, SAID THERMAL SINK BEING ADAPTED TO CARRY OFF VAPOR FROM SAID COLUMN AND CONDENSE THE SAME, A DISTRIBUTOR FOR CONDENSATE RETURNING TO SAID COLUMN, CONDUIT MEANS IN THE INSULATED PORTION OF SAID COLUMN CONNECTING SAID THERMAL SINK TO THE UPPER PART OF SAID COLUMN, SAID CONDUIT MEANS COMMUNICATING WITH SAID DISTRIBUTOR FOR THE CONDENSATE RETURNING TO SAID COLUMN AND A VAPOR LIFT PUMP IN THE INSULATED PORTION OF SAID COLUMN OPERATIVELY CONNECTED TO SAID DISTRIBUTOR, A HEAT CONDUCTIVE MEMBER IN SAID COLUMN HAVING AN EXTERNAL SOURCE OF APPLIED HEAT AND BEING IN HEAT CONDUCTING RELATIONSHIP WITH SAID VAPOR LIFT PUMP, SAID RETURNING CONDENSATE BEING CONDUCTED TO THE LOWER END OF SAID VAPOR LIFT PUMP WHEREBY SAID CONDENSATE IS CAUSED TO RISE THEREIN DUE TO SAID SOURCE OF APPLIED HEAT UNTIL IT SPILLS INTO SAID COLUMN, A PORTION OF SAID HEAT CONDUCTIVE MEMBER BEING ADAPTED TO ASSUME A TEMPERATURE HIGHER THAN THAT OF SAID CONDENSATE, A CONTROL ELEMENT IN SAID BOILER FOR AUTOMATICALLY CONTROLLING THE LEVEL OF LIQUID IN THE BOILER BEING REDUCED IN CROSS-SECTION AT THE END CLOSEST TO THE BOTTOM OF SAID BOILER, SAID HEAT CONDUCTIVE MEMBER BEING OPERATIVELY CONNECTED TO SAID ELEMENT, SAID CONTROL ELEMENT BEING IN HEAT EXCHANGING CONTACT WITH THE LIQUID IN SAID BOILER, AND SAID REDUCED END OF THE CONTROL ELEMENT BEING SO SHAPED AND PROPORTIONED THAT THE THERMAL RESISTANCE OF THE ELEMENT VARIES AT DIFFERENT DISTANCES BETWEEN THE JUNCTION OF THE ELEMENT WITH THE HEAT CONDUCTIVE MEMBER AND THE LIQUID LEVEL INSIDE SAID BOILER. 